Safety valve

The invention concerns a safety valve, in particular for low pressures and aggressive media, with an inlet which ends at the top in a valve seat upon which lies in a sealing manner a weight-loaded sealing body. A certain overpressure below the valve seat and/or a certain underpressure above the valve seat causes the sealing body to lift. At its upper end, the sealing body forms a shaft projecting vertically upward which is guided along or in a vertical part fixed immovably to the valve body. Fastened along or on top of the shaft are two or more weights, particularly detachable weights.